Writing instrument



FIG. 1 is a front elevational view of a writing instrument showing my new design with a clip member in a closed position;

FIG. 2 is a right side elevational view, the left side being a mirror image thereof;

FIG. 3 is a bottom plan view;

FIG. 4 is a front elevational view with a clip member in a raised position; and

FIG. 5 is a right side elevational view of FIG. 4, the left side being the mirror image thereof. 

The ornamental design for a writing instrument, as shown and described. 